The Value of Merely Imagining a Test

The value of a detailed test case increases if you don’t perform it and decreases when you do perform it.

The increased value comes from mentally walking through the test, which forces you to consider as many details as you can without interacting with the product-under-test. This is more valuable than doing nothing.

The decreased value comes from interacting with the product-under-test, which helps you learn more than the test case itself taught you.

What’s the takeaway? If an important test is too complicated to perform, we should at least consider writing a detailed test case for it. If you think you can perform the test, you should consider not writing a detailed test case and instead focusing on the performance and taking notes to capture your learning as it occurs.